Low profile rigid frame metal building



Nov. 11, 1969 b. RpGRAHAM LOW PROFILE RIGID FRAME METAL BUILDING 3Sheets-Sheet 1 Filed July 24, 1967 INVENTOR.

5 W m A d. m0 r r G Mr R 7 w 9 a w 9 V Nov. 11; 1969 D. R. GRAHAM3,477,183

LOW PROFILE RIGID FRAME METAL BUILDING Filed July 24, 1967 3 Sheets-Shedz INVENTORQ EM 5 flay/a A. Graham YOU/J97 Tho/20,0500

. ATTORNEYS Nov. 11, 19 69 GRAHAM 3,477,183

LOW PROFILE" RIGID FRAME METAL BUILDING Filed July 24, 1967 sShets-Sheet s INVENTOR.

08 W0 H Graham YOU/)9 Thompson ATTORNEYS United States Patent US. C].52-73 4 Claims ABSTRACT OF THE DISCLOSURE A low profile rigid framemetal building of very wide span is characterized by a column pinned tothe rafter intermediate the length of the rafter and guy cablesinterconnecting the upper end of the column and spaced points along therafter located in rigid regions of the rafter, a fluid dashpotinterconnects the upper free ends of opposed pairs of rafters, acrossthe center line of the building, to damp relative movement of the freeends, a sliding connection between the free ends also prevents them frommoving out of their common plane, and a ridge cap is pivotally carriedby the upper ends of the rafters.

The present invention relates to low profile rigid frame metalbuildings, of the type in which rafters inclined at a relatively smallpitch angle are rigid at their lower ends with the columns adjacent aside wall of the build ing. Such constructions are useful in metalbuildings having a ridge along the center line of the building, withpairs of rafters disposed in common vertical planes and their upper endsadjacent each other. Such construction is also useful in metal buildingsthat are open on one side such as airplane hangars or other cantileveredbuildings, in which case the upper ends of the rafters are at one sideof the building.

Among the objects of the invention are the provision of a low profilerigid frame metal building which will have a maximum of useable interiorspace, which will so distribute the bending moments in the columns andrafters that less steel will be required in its construction, that willbe free from destructive rhythmic motion under the influence of wind orother unequal loads, that will enable the construction of buildings ofgreatly increased span between columns, that will accommodate to snowload, and that will be relatively easy and inexpensive to manufactureand erect and rugged and durable in use.

Other objects and advantages of the present invention will becomeapparent from a consideration of the following description, taken inconnection with the accompanying drawings, in which:

FIG. 1 is a somewhat diagrammatic view in cross section of the frame ofa metal building according to the present invention;

FIG. 2 is a moment diagram showing the magnitude and distribution of thebending forces in a ratfer and rigidly attached column of a buildingaccording to the invention;

FIG. 3 is an enlarged fragmentary perspective view of the connectionbetween the upper adjacent ends of opposed rafters, that is, in theregion of the center of FIG. 1;

FIG. 4 is a top plan view, with parts broken away, of the structure ofFIG. 3;

FIG. 5 is a side elevational view of the structure of FIGS. 3 and 4showing the mounting of the ridge cap;

FIG. 6 is an enlarged fragmentary perspective view of the pin connectionbetween a rafter and the column which is intermediate the length of therafter;

FIG. 7 is a side elevational view, with parts broken away, of thestructure of FIG. 6;

FIG. 8 is a fragmentary perspective view of the assembly of rafters andpurlins;

FIG. 9 is an enlarged fragmentary elevational cross sectional view ofthe structure of FIG. 8, looking endwise of a rafter; and

FIG. 10 is a still further enlarged fragmentary perspective view showingan expansion joint between purlin ends.

Referring now to the drawings in greater detail, there is shown a lowprofile rigid frame metal building indicated generally at 1 comprising aplurality of first columns 3 disposed in vertical files at oppositesides of the building. For simplicity, it will be understood that onlyone set of columns 3 and the associated building structure are shown inFIG. 1, it being understood that the structure of FIG. 1 is duplicatedas many times as desired, on opposite sides of the plane of FIG. 1thereby to provide a metal building of any desired length. Inclinedratfers 5 in the form of steel box girders are provided, which arerigidly secured at their lower ends to the upper ends of columns 3 andare relatively free or non-load bearing at their upper ends. Secondcolumns 7, which are of a height such that their upper ends extendsubstantial distances above rafters 5, are provided which are disposedintermediate the length of rafters 5 but closer to columns 3, and areinclined upwardly in the direction of columns 3.

Pins 9 interconnect rafters 5 and columns 7 for relative verticalswinging movement. In the illustrated embodiment, columns 7 are cut andrafters 5 pass through them, the pins 9 being carried by columns 7 andpassing through rafters 5. Guy cables 11 extend from the top of secondcolumns 7 and are secured to rigid portions of rafters 5 at points thatare spaced from each other and spaced substantial distances from columns7. Preferably, the guy cables 11 extend in both horizontal directionsfrom columns 7.

The upper ends 13 of the rafters 5 are disposed adjacent each other inthe embodiment shown in FIG. 1. It will be understood, however, that theportion of the building on either side of its longitudinal center lineis usable as a cantilever type building.

The rafters 5 carry horizontal purlins 15 that extend perpendicular toand are secured to the upper sides of rafters 5. Braces 17 extenddiagonally between purlins 15 and lower portions of rafters 5. Certaincontiguous ends of purlins 15 are provided with slide joints 19 so as toaccommodate thermal expansion and contraction and other influences thatcause the ends of purlins 15 to move relative to each other.

Of course, purlins 15 support the usual roof sheets (not shown).

The ends 13 of each pair of opposed rafters 5 are interconnected by ahydraulic dash pot 21, including a cylinder 23 that is pivotally securedfor vertical swinging movement on and relative to one end 13 of onerafter 5, While its corresponding piston and piston rod 25 are pivotallymounted for vertical swinging movement on and relative to the other end13 of the other rafter 5 of the pair. The axis of dash pot 21 issubstantially horizontal. The cylinder 23 of dash pot 21 is filled witha hydraulic liquid on opposite sides of piston 25, and piston 25provides for passage of the liquid from one side to the other of piston25, thereby to damp movement of the ends 13 in both horizontaldirections in their common plane. Preferably, piston 25 has one-wayvalve means (not shown) therein, to permit free collapse of dash pot 21but yieldingly to resist extension of dash pot 21. Of course, theone-way valve means could be reversed so as to act the other way, oreliminated so that movement in both directions was yieldingly resisted.

Shear plates 27 are also provided, which are disposed in vertical planesand secured to opposite sides of one of the ends 13 and slidablyreceived on opposite sides of the other end 13 in guides 29. Shearplates 27 thus prevent movement of ends 13 relative to each other out oftheir common plane, that is, parallel to the planes of the building,While at the same time permitting movement of ends 13 toward and awayfrom each other parallel to the axis of dash pot 21. Shear plates 27 andtheir guides 29 also maintain ends 13 at a common horizontal level so asto avoid differential vertical displacement of ends 13.

A ridge cap 31 is disposed above and closes the gap between ends 13 andextends full length of the building. Ridge cap 31 is carried by brackets33 on each of ends 13, as seen in FIG. 5. Struts 35 are pivotallyinterconnected at 37 to brackets 33 and at 39 to ridge cap 31, therebyto support ridge cap 31 on brackets 33 and at the same time to permitmovement of ends 13 relative to each other and to ridge cap 31. Screens41 close the gap between brackets 33 or the adjacent purlin 15 on theone hand, and ridge cap 31 on the other hand. Ridge cap 31 thus rendersthe ridge of the building weather tight while at the same time providingventilation for the interior of the building.

FIG. 2 shows the moment diagram for a building according to the presentinvention. It will be apparent from FIG. 2 that the bending moments aregreatest adjacent the haunch between the columns 3 and the rafters 5, asis usual in rigid frame buildings of this type. It is for this reason,of course, that the columns 3 are wider adjacent their upper ends thanadjacent their lower ends. Similarly, the moment diagram of FIG. 2 showsthat a portion of the weight of rafters 5 is borne by the pin 9, andthat bending stresses of course tend to concentrate along the rafter atthe points of connection of the guy cables 11. It will also be apparentfrom the moment diagram of FIG. 2 that rafter 5 could be in sectionswith pivotal joints disposed at any or all of the points where thebending moment is zero; but it is preferred that rafter 5 be rigid alongits full length. Finally, it will be apparent from the moment diagram ofFIG. 2 that a construction has been achieved in which the bendingmoments are so distributed that the rafters 5 can be made of desirablylightweight and hence inexpensive construction, with a consequentreduction in the weight and cost of the building. At the same time, thefree or upper ends of the rafters 5 can be non-load bearing and movablerelative to each other, thanks to the special arrangements shown inFIGS. 3 to 5.

From a consideration of the foregoing disclosure, therefore, it will beevident that all of the initially recited objects of the presentinvention have been achieved.

What is claimed is:

1. A support for a portion of a low profile metal building comprising aninclined rafter, a first column rigid with the lower end of the rafter,a second column intermediate the ends of the rafter, meansinterconnecting the rafter and the second column for relative verticalswinging movement, the portions of the rafter on opposite sides of thesecond column being rigid with each other, the second column extending asubstantial distance above the rafter, first guy means interconnectingthe second column a substantial distance above the rafter with aplurality of spaced points intermediate the length of the rafter asubstantial distance from the second column and on the side of thesecond column opposite the first column, and second guy means anchoringthe second column a substantial distance above the rafter to a point onthe same side of the second column as the first column, the rafter beingsubstantially rigid throughout its length.

2. A support as claimed in claim 1, there being a pair of opposed andoppositely inclined said rafters that lie in a common vertical plane andwhose upper ends are disposed adjacent each other to define a ridge forthe building, and means interconnecting said upper ends of the raftersand preventing substantial movement of the rafter ends relative to eachother out of said plane while permitting substantial movement of saidrafter ends relative to each other in said plane, said preventing meanscomprising guide means slidably interconnecting said rafter ends onopposite sides of at least one of said rafter ends.

3. A support as claimed in claim 1, there being a pair of opposed andoppositely inclined said rafters that lie in a common vertical plane andwhose upper ends are disposed adjacent each other to define a ridge forthe building, a ridge cap for the building, means pivotallyinterconnecting the ridge cap with one of said adjacent rafter ends forrelative vertical swinging movement about a first horizontal axis, andmeans pivotally interconnecting the ridge cap with the other of saidadjacent rafter ends for relative vertical swinging movement about asecond horizontal axis spaced from and parallel to said first axis.

4. A support as claimed in claim 1, said second guy means being anchoredto said support adjacent the junction of said first column and saidinclined rafter.

References Cited UNITED STATES PATENTS 1,419,868 6/1922 Levitan 52-831,689,131 10/1928 Goodwin 52-1 2,053,226 9/1936 Ruge 52167 3,138,8286/1964 Greenbie 52-90 FRANK L. ABBOTT, Primary Examiner S. D. BURKE,III, Assistant Examiner US. Cl. X.R. 5290, 94, 146, 167

